What they represent
A corneal ulcer is a disruption or open sore in the outer surface (epithelial) layer of the cornea. Corneal ulcers are frequently caused by some form of eye injury. Infection, dry eye, foreign bodies and abnormal eyelashes are other common culprits. Typical healing time for most superficial ulcers is 3-5 days. Ulcers that remain superficial and do not progress to healing (although often fluctuate in size) may be indolent. Other names for this type of ulcer are boxer ulcer, refractory ulcer, chronic corneal erosion, and spontaneous chronic corneal epithelial defect (SCCED).
Diagnosis
Indolent corneal ulcers occur most often in middle aged to older dogs. While they can affect dogs of any breed, the Boxer is most commonly affected. The exact cause of the poor corneal healing is unclear, but is thought to be due to a defect involving the attachment of the corneal epithelial basement membrane to the adjacent stroma. An indolent ulcer, without specific therapy, can last for weeks to months, and be associated with chronic eye pain and potential vision loss. Fluorescein stain is used to diagnose an ulcer, which classically migrates beneath the ulcer’s loose, nonadherent epithelial margins. In addition, a thorough ophthalmic exam is essential to ensure there are no other reasons why the ulceration has not healed, such as the presence of infection, dry eye, foreign body or abnormal eyelash.
Treatments
There are number of treatments available to promote successful healing of indolent ulcers in dogs. Keratotomy (grid or punctate) and a keratectomy are procedures associated with the highest success rates for healing. Keratotomies facilitate ulcer healing in 95%+ of affected patients. It can usually be performed after instillation of topical anesthetic, and involves superficial scoring of the ulcer with a fine needle. This exposes the deeper, healthier corneal tissues of the ulcer bed and gives the fresh epithelial cells growing over the ulcer something to hold anchor / adhere to. This procedure is often combined with a diamond burr polishing technique, which by itself, is also a very highly-effective treatment for facilitating ulcer healing. In cases where indolent ulcers are nonresponsive to keratotomy, a keratectomy is the ideal option. This surgery is associated with nearly a 100% success rate. The main disadvantages are that it requires general anesthesia in addition to being more costly than a keratectomy.
Regardless of the procedure performed to promote healing, after care involves placement of contact lens, to improve comfort as the ulcer is healing, and topical antibiotics to limit the risk of infection during the healing process. Oral medications are also recommended to control any eye pain until healing is complete. It is crucial that your pet not rub at the eye and interfere with healing. A protective Elizabethan collar will used to prevent this problem. Due to the potential for recurrence of indolent ulcers, this condition can be frustrating in the more severely affected patients. Fortunately, most dogs will heal well after the keratotomy procedure. With patience and team work we will help the ulcer to ultimately heal, and restore comfort in your dog as soon as possible.